1. Field of the Invention
The present invention relates to an optical pickup device and more particularly to an optical pickup device to be used in a system for optically reading out recorded information.
2. Description of Background Information
In the case of the conventional optical pickup device, it is necessary to use a prism for separating a reflection light beam from a read-out light beam emitted from a light source. The half prism or the Wollaston prism (Wollaston double image prism) are examples of such a prism. In the case of the half prism, the reflection beam emerging from the prism is directed substantially normal to the path of the read-out light beam. Therefore, the size, especially the width, of the pickup device inevitably becomes large, which further becomes an obstacle to the reduction in size of the system as a whole. With a Wollaston prism, the disadvantage is that the production cost is substantially high.